Buying a Used Car.

[Krisjones360]

I recently bought a used car (62plate focus Zetec S).

When I veiwed the car and agreed to payments and part ex and everything it had Michelin Pilot Sport 3 tyres on. But when the vehicle has arrived they've been replaced with Triangles(budget brand). They said the other tyres were worn and needed replacing, my argument is, if they needed replacing why was I allowed to test drive? And if they replace tyres after the sale are they even allowed to change them without my consent?

Thanks guys(and girl)